Nato is “relying” on the UK to spend billions more on its military to help protect Europe, according to the alliance’s chief, even as the British government mulls further deep cuts to budgets across Whitehall, including at the Ministry of Defence.

The UK and Italy are now alone among Nato’s largest allies in not having committed to extra defence spending in light of Russia’s belligerence in Ukraine, the terrorist resurgence in the Middle East and the mounting refugee crisis in the Mediterranean...............